Improving Stern Thruster Access

[tlkenyon]

As i knew (and dreaded) it would happen sooner or later, the shear pin on my stern thruster failed...2015 R25SC. I have neck and shoulder issues, and cannot get to the two bolts with enough oomph to do the shear pin change, even with the provided ratchet tool. I might be able to get the bolts undone, but no way am I gonna be able to get it put back together.

As I am in South Dakota, a long, long ways from a boat shop that could do this, and because we are often on very remote waters out on the prairie, I need to figure out a way to do this myself.

I am thinking about cutting out the front of the panel as shown by the shaded areas on the photo. I would place cleats, either teak or stainless, much like a sailboat companionway, to secure the panel in place. With the panel out, it seems like access to the stern thruster would quite easy....even for me.

Whaddya think? Bad idea? Good idea? Pitfalls?

THANKS

TK

 

[Lobo]

Good idea. I cut out centre post and reinstalled with hinges. It makes it easy for me to remove the whole door assembly for extra room. Your idea looks neater. I hide mine behind a sunbrella snap on cover I had made. Unless I have the cover off, I can't see what the front of my locker looks like.

Yes, you have a problem in getting to the thruster motor. Skinny, strong and young beats geezer!

I added about 14" of chain into two of the thruster surround bolts. Gives me a handle AFTER I remove the two bolts that are causing you a problem.

I've cut into the scupper drain hose in the battery compartment to get an arm down. Move it out of the way -- and remember to tape it back up!

You may end up removing the lid on the deck inside the locker to get a bit more room. Certainly you have to rig the lid so it stays up and out of your way.

I felt that a good days work was just getting the motor off. Found out it took 2 days! Easy to change the broken shear pin, but it's as bad -- if not worse -- reinstalling the motor. This is where the chain handle comes in handy. Hook a line through the chain, out the top, block and tackle to a barn rafter -- you CAN make it work!

Sort of related: I've put in a composting toilet and threw out the holding tank. Next time the pin breaks, I'll go in that way.

I'm not sure a marine mechanic would do any better -- unless he was young, strong and skinny.

Dave
Lobo

 

[knotflying]

Your idea looks good. I would only be concerned that the sides may lose stability and cracks could form near the base. I was think that if and when the time comes I may just cut out a square access leaving a piece across the top. I haven't thought about what the panel will be or perhaps make a removable frame with the cut out fiberglass in the center. A job dreaded by all of us!

 

[tugnnaweigh]

Just finished this chore, here's what I learned:

REMOVAL: Only things in the way that had to be removed were two of the four batteries and some of the exhaust system. Then I had to put a cheater bar on the ratchet to break the fasteners loose. I unscrewed the first fastener until I couldn't get the ratchet out, so then I had to buy another ratchet. So just back each fastener out a little bit, working from side to side while pulling the thruster away from the transom mount to avoid ending up in this situation. I then lifted it out by gently holding it by the three electrical lines that go in its back.

INSTALLATION: i built handles out of packing tape per a tip here on the 'Nuts and lowered the thruster into place with the fasteners hanging it their holes. I found a 2 X 4 underneath held the thruster at the right elevation leaving just left to right and clockwise and counter clockwise adjustments necessary. Found out two people can't do it, need one on the propeller to wiggle it so the thruster will flush out with the mount. Then one person pushes it into the mount and rotates it per the instructions of the other person who's on the fastener on the side opposite of the first guy. As the fastener guy you're feeling for that tiny catch or wiggle or feedback that means the fastener is at the threaded opening and then you turn the fastener as much as you can by hand before sinking the other one by hand and proceeding to the ratchet for the final tightening. To help this I cleaned the threads of the fastener and used WD 40 on the threaded holes.

PICTURES: There's pics of much of this in my album, looking back, it actually came out fairly easily, get everything out of the way and then you're just unscrewing two fasteners; for the install have three folks and be ready for a bit more of a tussle.

On the Beer and Band Aids Scale I give the removal a 6.6 and the install a 9.2. Hope this is helpful.

 

[CAPTCRUNCH]

I wonder if the proposed drop-in panel would still support the cockpit table.

 

[tlkenyon]

The intent is that the drop-in panel would indeed support the table, but if not, a small price to pay.
TK

 

[captstu]

I'm thinking of replacing the shear pin with an up breakable steel pin. The design is poor, the pin breaks without warning and would be better if it were a prop shear pin or none at all, just a fuse.

Why does ranger still use such a poor design?

 

[tlkenyon]

I have been thinking the same thing....a steel pin. If there is a clog, wonder what breaks?
TK

 

[captstu]

TK,

I don't think anything fails except the shear pin. The prop is much less expensive and easier to replace if it fails, but a line in the prop, the most common cause of failure, just pops the fuse.

I've long since replace the foolish OEM fuse with an easy to change fuse of the same rating - no problem to swap underway.

I don't think much of boat designs that can't be repaired by a capable owner (Ive removed heads and swapped pistons on previous sailboats). I just can't reach the shearpin even after taking everything in the way out of the boat.

Last pin failure, I contacted a local Side Power dealer who charged me $250 to put the bolts back in - after I took everything out and removed the motor. Even then, the guy only put in one stud/nut - left the other one on the shelf saying he couldn't get it in place.

The owner of the shop sent someone else out who put the stud/nut back in and told me, "NEVER AGAIN".

I either have to give up the stern thruster, find a tall thin buddy, or find a replacement for the Side Power. These just don't belong on a boat owned by someone over 70.

If you come up with a replacement . . .

 

[blifland]

Here is what else that can fail or break besides the shear pin:
The gearhead gears can strip very easily. The internal gears are not repairable or replaceable; the whole gearhead must be replaced.
Bow thruster gearhead price: $460 to $500 depending where purchased. Have no idea what the stern gearhead costs should it be different than the bow unit.
A few months ago, while docking at a busy resort dock - a number of people volunteered to help before we were ready and I lost track of the port bow line - thruster pulled it in then sent it out same port side, wrapping around the gearhead in the tunnel. The shear pin did not break, the gears did - still working somewhat, but with a terribly loud grinding noise that Side Power told me will completely fail very soon.